1. Field of the Invention
The present invention relates to the field of liquid crystal displaying techniques, and in particular to a liquid crystal display panel and array substrate thereof.
2. The Related Arts
As the displaying technique continues to grow, the three dimensional (3D) displaying technique is also becoming more matured. A variety of 3D image equipments, such as, 3D TV, 3D projection, 3D camera, is becoming available in the market. Compared to a two dimensional (2D) displaying technique, the display of 3D displaying technique is more vivid and shows better visual effects. Three dimensional displaying is becoming a mainstream of the future display device.
Film-type patterned retarder (FPR) is one of the 3D liquid crystal imaging techniques. As shown in FIG. 1, FPR 3D display system includes a liquid crystal display panel 11, patterned retarder thin film 12 and patterned retarder eyeglasses 13. Liquid crystal display panel 11 includes pixel 16 forming left-eye signal, pixel 17 forming right-eye signal and black matrix (BM) 18 between pixel 16 and pixel 17. FPR 3D display system mainly uses patterned retarder thin film 12 attached to liquid crystal panel 11 to separate 3D image into left-eye image 14 and right-eye image 15. Then, through patterned retarder eyeglasses 13, left-eye image 14 and right-eye image 15 are sent to left eye and right eye of the user respectively. The left eye and right eye of the user receive the two sets of images and the brain synthesizes the two image sets into a 3D image.
Because FPR 3D displaying technique does not require opening and closing of a lens, FPR 3D display system shows less flickering in the display and achieves better visual experience; especially, when working with vertical alignment (VA) display panel to view 3D images, the result is even better. This is because VA display panel, compared to known display panel, has high contrast and short response time, and can provide better display result. However, VA panel is deficient in screen uniformity so that color drift often occurs. When viewed in large view angle, the color cast is easily detectable. Also, FPR 3D displaying technique also suffers the problem of view angle restriction, i.e., the viewer has a narrower view angle. When the viewer is at the position of larger view angle, the two eyes may suffer signal crosstalk, for example, the signal that should be sent to right eye is seen by the left eye, shown as the dash-line in FIG. 1. This situation leads to serious image crosstalk and results in poor image clarity. Therefore, when realizing FPR 3D displaying technique on VA display panel, the large view angle problem is severe.
In known techniques, the solution to solve the above view angle restriction problem of FPR 3D displaying technique is usually to increase the width of BM 18 between pixel 16 forming left-eye signal and pixel 17 forming right-eye signal in order to reduce possible signal crosstalk between two eyes, as shown in FIG. 1. The computation shows that the width of BM 18 must increase to ⅓ width of the pixel to be effective in reducing crosstalk. However, this approach will result in opening ratio of the pixel greatly reduced, and the luminance of liquid crystal display panel will also be reduced. In particular, when in 2D display mode, there is no crosstalk problem between two eyes, and yet luminance is still reduced. On the other hand, when 2D display panel is transformed into a panel able to display 2D and 3D images, the transformation can be realized by manufacturing a BM mask. After increasing width of BM 18, corresponding BM mask must also be modified and thus manufacture cost of liquid crystal display panel is increased.
Another approach is to use one gate line two data line (1G2D) pixel design. As shown in FIG. 2, a pixel structure using 1G2D pixel design includes a first data line 21, a second data line 22, a scan line 23, a main pixel 24 and a sub pixel 25. First data line 21 and second data line 22 supply signal to main pixel 24 and sub pixel 25. Main pixel 24 and sub pixel 25 are driven by same scan line 25. When liquid crystal display panel switches from 2D display mode to 3D display mode, black screen signal is inputted to main pixel 24 to display the color black to realize BM effect in main pixel area and to reduce signal crosstalk between two eyes. Main pixel 24 and sub pixel 25 of 1G2D pixel design have different liquid crystal rotation angles so that liquid crystal panel has good low color cast effect in 2D display mode. However, when switching to 3D display mode, because main pixel 24 is black, only liquid crystal rotation of sub pixel 25 is shown, and the low color cast effect is lost. In addition, VA display panel exists own color cast, the color anomaly observed by the viewer at position with large viewing angle is even more severe.